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Computational Techniques for Structural Health Monitoring
Computational Techniques for Structural Health Monitoring [1852]
Автор(ы): Srinivasan Gopalakrishnan, Massimo Ruzzene, Sathyanarayana Hanagud
Издательство: Springer-Verlag (www.springer.com)
Количество страниц: 505
Год: 2011
Аннотация[228 КБ] 
Код: 10106
Описание
The increased level of activity on structural health monitoring (SHM) in various universities and research labs has resulted in the development of new methodologies for both identifying the existing damage in structures and predicting the onset of damage the may occur during service. Designers often have to consult a variety of textbooks, journal papers and reports, because many of these methodologies require advanced knowledge of mechanics, dynamics. Wave propagation, and material science. Computational Techniques for Structural Health Monitoring gives a one-volume, in-depth introduction to the different computational methodologies available for rapid detection of flaws in structures. Techniques, algorithms and results are presented in a way that allows their direct application. A number of case studies are included to highlight to further the practical aspects of the selected topics. Computational Techniques for Structural Health Monitoring also provides the reader with numerical simulation tools that are essential to the development of novel for the interpretation of experimental measurements, and for the identification of damage and its characterization. Upon reading Computational Techniques for Structural Health Monitoring, graduate students will be able to begin research-level work in the area of structural health monitoring. The level of detail in the description of formulation and implementation also allows engineers to apply the concepts directly in their research.
Содержание
Part I Introductory Concepts in Structural Health Monitoring
1. 1 Introduction
1.1. 1.1 Overview on Structural Health Monitoring
1.1.1. 1.1.1 Why Do We Need Structural Health Monitoring?
1.1.2. 1.1.2 Basic Elements of SHM Systems
1.1.3. 1.1.3 Levels of Structural Health Monitoring
1.1.4. 1.1.4 State-of-Art and Technological Needs
1.2. 1.2. Dynamics-Based Structural Health Monitoring
1.2.1. 1.2.1 Passive SHM
1.2.2. 1.2.2 Classification of Inspection Techniques Based on Frequency Range of Analysis
1.2.3. 1.2.3 Vibration-Based Techniques
1.2.4. 1.2.4 Guided Waves Inspection
1.2.5. 1.2.5 Ultrasonics and Nonlinear Ultrasound
1.3. 1.3 Sensing and Actuation Strategies
1.3.1. 1.3.1 Piezoelectric Actuators and Sensors
1.3.2. 1.3.2 Fiber Optics Sensors
1.3.3. 1.3.3 Laser Vibrometer
1.4. 1.4 Modeling and Simulation Techniques for SHM
1.4.1. 1.4.1 The Importance of Modeling in Structural Health Monitoring
1.4.2. 1.4.2 Finite Difference Techniques
1.4.3. 1.4.3 Finite Element Method
1.4.4. 1.4.4 Boundary Element Method
1.4.5. 1.4.5 Spectral Finite Element Method
1.4.6. 1.4.6 Perturbation Techniques
1.5. 1.5 Organization of the Book
1.6. References
2. 2 Fundamentals Concepts in Elasticity, Mechanics and Wave Propagation
2.1. 2.1 Introduction
2.2. 2.2 Basic Concepts in Elasticity
2.2.1. 2.2.1 Description of Motion
2.2.2. 2.2.2 Strain
2.2.3. 2.2.3 Strain-Displacement Relations
2.2.4. 2.2.4 Stress
2.2.5. 2.2.5 Constitutive Relations
2.2.6. 2.2.6 Elastic Symmetry
2.3. 2.3 Governing Equations of Motion and the Solution Methods
2.3.1. 2.3.1 Solution Procedures in Linear Theory of Elasticity
2.3.2. 2.3.2 Plane Problems in Elasticity
2.4. 2.4 Introduction to Theory of Composites
2.4.1. 2.4.1 Theory of Laminated Composites
2.4.2. 2.4.2 Stress-Strain Relation for a Lamina with Arbitrary Orientation of Fibers
2.5. 2.5 Introduction to Wave Propagation in Structures
2.5.1. 2.5.1 Spectral Analysis
2.6. 2.6 Characteristics of Waves in Anisotropic Media
2.7. 2.7 Governing Equations for Beams and Plates
2.7.1. 2.7.1 Governing Equation for an Elementary Beam
2.7.2. 2.7.2 Governing Differential Equation for a Higher Order Beam
2.7.3. 2.7.3 Governing Equations for a Composite Plate
2.8. 2.8 Spectrum and Dispersion Relations
2.8.1. 2.8.1 Efficient Computation of the Wavenumber and Wave Amplitude
2.8.2. 2.8.2 Spectrum and Dispersion Relation for an Elementary Beam
2.8.3. 2.8.3 Spectrum and Dispersion Relation for a Higher Order Beam
2.8.4. 2.8.4 Spectrum and Dispersion Relation for an Anisotropic Plate
2.9. References
3. 3 Signal Processing Techniques
3.1. 3.1 Integral Transforms
3.1.1. 3.1.1 Fourier Transformsm
3.1.2. 3.1.2 Fourier Series
3.1.3. 3.1.3 Discrete Fourier Tran sform
3.1.4. 3.1.4 Wavelet Transforms
3.1.5. 3.1.5 Wavelet-Based Numerical Solutions of Wave Equations
3.1.6. 3.1.6 Comparative Advantages and Disadvantages of Different Transforms
3.2. 3.2 Signal Processing Issues
3.2.1. 3.2.1 Wraparound Problems
3.2.2. 3.2.2 Signal Processing of Sampled Waveforms
3.2.3. 3.2.3 Artificial Dispersion in Wavelet Transform
3.2.4. 3.2.4 Excitation Signals and Wave Dispersion
3.3. 3.3 Frequency/Wavenumber Analysis
3.3.1. 3.3.1 Analysis of a One-Dimensional Propagating Wave
3.3.2. 3.3.2 Analysis of 2D Wave Propagation
3.3.3. 3.3.3 Numerical Examples: Wave Propagation in a Damaged Rod
3.3.4. 3.3.4 Numerical Examples: Wave Propagation in a Homogeneous Medium
3.3.5. 3.3.5 Frequency/Wavenumber Filtering for Mode Separation
3.4. References
Part II Computational Simulation Techniques for Structural Health Monitoring
1. 4 Application of the Finite Element Method in SHM
1.1. 4.1 Overview and Basic Principles
1.2. 4.2 Modeling Issues in FEM
1.3. 4.3 Damage Modeling Using FEM
1.3.1. 4.3.1 Stiffness Reduction Method
1.3.2. 4.3.2 Duplicate Node Method
1.3.3. 4.3.3 Kinematics Based Method
1.4. 4.4 Numerical Examples
1.4.1. 4.4.1 Static and Free Vibration Analysis of a Damaged Cantilever Beam Using DNM
1.4.2. 4.4.2 Response Analysis of a Cantilever Composite Beam with Different Damage Types
1.5. 4.5 Finite Element Modeling Suggestions
1.6. 4.6 Modeling Pitfalls in FEM for SHM and Their Remedies
1.7. References
2. 5 Spectral Finite Element Method
2.1. 5.1 The Need for Spectral FEM in SHM
2.1.1. 5.1.1 General Formulation Procedure: Fourier Transform Based SFEM
2.1.2. 5.1.2 General Formulation Procedure: Wavelet Transform Based SFEM
2.2. 5.2 Spectral Elements for Rods and Beams
2.2.1. 5.2.1 Non-dispersive Isotropic Rod: FFT Based Spectral Element Formulation
2.2.2. 5.2.2 Non-dispersive Isotropic Rod: Wavelet Transform Based Spectral Element Formulation
2.2.3. 5.2.3 Dispersive Isotropic Timoshenko Beams-FFT Based Spectral Element Formulation
2.2.4. 5.2.4 Composite Beams-FFT Based Spectral Element Formulation
2.2.5. 5.2.5 Higher Order Composite Beam-FFT Based Spectral Element Formulation
2.3. 5.3 Spectral Elements for 2D Composite Layers-FFT Based Spectral Element Formulation
2.3.1. 5.3.1 Finite Layer Element (FLE)
2.3.2. 5.3.2 Infinite Layer (Throw-Off) Element (ILE)
2.3.3. 5.3.3 Expressions for Stresses and Strains
2.3.4. 5.3.4 Prescription of Force Boundary Conditions
2.3.5. 5.3.5 Determination of Lamb Wave Modes
2.4. 5.4 Anisotropic Plate-FFT Based Spectral Element Formulation
2.4.1. 5.4.1 Finite Plate Element
2.4.2. 5.4.2 Semi-infinite or Throw-Off Plate Element
2.5. 5.5 Numerical Examples
2.5.1. 5.5.1 Wave Transmission and Scattering Through an Angle-Joint
2.5.2. 5.5.2 Wave Propagation in 2D Portal Frame
2.5.3. 5.5.3 Propagation of Surface and Interfacial Waves in a Composite Layer
2.5.4. 5.5.4 Propagation of Lamb Wave
2.5.5. 5.5.5 Wave Propagation in a Composite Plate with Ply-Drop
2.6. 5.6 Conclusions
2.7. References
3. 6 Simplified Spectral Models for Damaged Waveguides
3.1. 6.1 Need for Spectral Element Damage Models in Structural Health Monitoring
3.2. 6.2 Review of Simplified Models for Structural Defects
3.3. 6.3 Modeling of Single Delamination or Horizontal Cracks
3.3.1. 6.3.1 Wave Scattering in a Delaminated Beam Using Wavelet Spectral Elements
3.3.2. 6.3.2 Effect of Wave Scattering Due to Delamination at Ply-drops
3.4. 6.4 Modeling of Fiber Breakage and Vertical Cracks
3.4.1. 6.4.1 Interface Equilibrium of Forces
3.4.2. 6.4.2 Assembly of the Element Internal Waveguides
3.4.3. 6.4.3 Modeling Dynamic Contact Between Crack Surfaces
3.4.4. 6.4.4 Modeling of Surface Breaking Cracks
3.4.5. 6.4.5 Distributed Constraints at the Interfaces Between Sub-Laminates and Hanging Laminates
3.4.6. 6.4.6 Wave Scattering Due to Transverse Cracks
3.4.7. 6.4.7 Sensitivity of the Fiber Breakage Location and Configuration
3.5. 6.5 Modeling of Structures with Multiple Horizontal Cracks or Delaminations
3.5.1. 6.5.1 Wave Scattering from Delamination: Comparison with 2D FEM
3.5.2. 6.5.2 Computational Efficiency of FSFEM Compared to FEM
3.6. 6.6 Modeling of Corrosion Pits
3.6.1. 6.6.1 Wave Propagation Response Due to Corrosion Pits
3.7. 6.7. Modeling of Material Degradations
3.7.1. 6.7.1 Experimental Degraded Model (EDM)
3.7.2. 6.7.2 Average Degraded Model
3.7.3. 6.7.3 Wave Scattering in a Degraded Composite Beam Using ADM
3.8. 6.8 Modeling of Vertical Cracks in 2D Waveguides
3.9. 6.9 Conclusions
3.10. References
4. 7 Perturbation Methods for Damaged Structures
4.1. 7.1 Perturbation Methods for Notched Structures
4.2. 7.2 Modal Analysis of Damaged Plates
4.2.1. 7.2.1 Governing Equations
4.2.2. 7.2.2 Perturbation Solution
4.2.3. 7.2.3 Fourier Series Solution of e1 Equations
4.2.4. 7.2.4 Strain Energy Ratio for Damage Localization
4.2.5. 7.2.5 Effect of Notch Damage on the Plate Modal Properties
4.2.6. 7.2.6 Notch Damage Localization Through the Strain Energy Ratio
4.2.7. 7.2.7 Effect of Line Damage on the Plate Modal Properties
4.3. 7.3 Analysis of Wave Propagation in Notched Beams Through Spectral FE Solution
4.4. 7.4 Governing Equations
4.4.1. 7.4.1 Spectral Finite Element Discretization
4.5. 7.5 Wave Propagation in Notched Beams: Numerical Examples
4.5.1. 7.5.1 Technique Validation: FSFEM Versus FE Predictions
4.5.2. 7.5.2 FSFEM and Modal Superposition Results
4.5.3. 7.5.3 Time Domain Results
4.5.4. 7.5.4 Frequency Domain Results
4.6. References
5. 8 Bridging Scale Analysis of Wave Propagation in Heterogeneous Structures with Imperfections
5.1. 8.1 Overview
5.2. 8.2 Theoretical Background
5.2.1. 8.2.1 Coarse and Fine Scale Discretization and Bridging Matrices
5.2.2. 8.2.2 Multiscale Lagrangian
52.3. 8.2.3 Reduction of the Degrees of Freedom
5.2.4. 8.2.4 Time Domain Formulation
5.2.4. 8.2.5 Frequency Domain Formulation
5.3. 8.3 Results for Time-Domain Bridging
5.3.1. 8.3.1 Application to a One-Dimensional Rod
5.3.2. 8.3.2 Homogenized Bi-material Rod with Imperfections
5.3.3. 8.3.3 Energy-Based Time Integration Scheme
5.3.4. 8.3.4 Propagation of In-plane Waves in a 2D Elastic Domain
5.4. 8.4 Results for Frequency-Domain Bridging
5.4.1. 8.4.1 Time Domain Spectral Element Discretization
5.4.2. 8.4.2 Rod
5.4.3. 8.4.3 Damaged Timoshenko Beam
5.4.4. 8.4.4 Two Dimensional Waveguides
5.5. 8.5 Conclusions
5.6. References
6. 9 Modeling of Actuators and Sensors for SHM
6.1. 9.1 Introduction
6.2. 9.2 Modeling of Lamb Wave Generation
6.2.1. 9.2.1 Governing Equations
6.2.2. 9.2.2 Harmonic Far Field Response
6.2.3. 9.2.3 Actuator Directivity
6.2.4. 9.2.4 Example: Circular Actuator
6.2.5. 9.2.5 Experimental Validation
6.2.6. 9.2.6 Finite Element Evaluation of the Interface Stresses
6.2.7. 9.2.7 Example: Circular Patch
6.2.8. 9.2.8 Rectangular Isotropic Piezo Patch
6.3. 9.3 Beamforming Through One-Dimensional Phased Arrays: A Quick Overview
6.3.1. 9.3.1 Response Due to a Single Component
6.3.2. 9.3.2 Array Response
6.3.3. 9.3.3 Beam Steering Strategies
6.4. 9.4 Two Dimensional Arrays for Frequency Based Beam Steering
6.4.1. 9.4.1 Application to SV Waves in a Membrane
6.4.2. 9.4.2 Application to Guided Waves in Thin Plates
6.5. 9.5 Modeling of Lamb Wave Sensors
6.5.1. 9.5.1 Plate Configuration and Piezoelectric Constitutive Relations
6.5.2. 9.5.2 Voltage Generated by Piezo Sensors of Arbitrary Shape
6.5.3. 9.5.3 Examples of Directivities for Simple Geometries
6.5.4. 9.5.4 Frequency Steerable Acoustic Transducer Periodic Array
6.6. References
Part III Computational Methodologies for Damage Detection and Quantification
1. 10 Computational Techniques for Damage Detection, Classification and Quantification
1.1. 10.1 Overview
1.2. 10.2 A General Introduction to Vibration-Based Techniques
1.2.1. 10.2.1 Early Techniques Based on Natural Frequency Shifts
1.2.2. 10.2.2 Mode Shape Analysis
1.2.3. 10.2.3 Mode Shape Curvature Changes
1.3. 10.3 Damage Measure Based on Energy Functional Distributions
1.3.1. 10.3.1 Formulation for Beams and Plates
1.3.2. 10.3.2 Spline Interpolation of Operational Deflection Shapes
1.3.3. 10.3.3 Numerical Results on Beams
1.3.4. 10.3.4 Numerical Results on Plates
1.3.5. 10.3.5 Experimental Results on Beams
1.3.6. 10.3.6 Experimental Results on Plates
1.4. 10.4 Wave Propagation Techniques: Time Domain Damage Measure
1.4.1. 10.4.1 Theoretical Background
1.4.2. 10.4.2 Numerical Examples: Wave Propagation in a Homogeneous Medium
1.4.3. 10.4.3 Experimental Results: Aluminum Plate
1.5. 10.5 Phase Gradient and Conversion Coefficients Evaluation for Damage Localization and Quantification
1.5.1. 10.5.1 Simplified Description of a Multi-Modal Wave
1.5.2. 10.5.2 Phase Gradient for Damage Localization
1.5.3. 10.5.3 Reflection, Transmission and Conversion Coefficients for Damage Quantification
1.5.4. 10.5.4 Application to Simulated Data
1.5.5. 10.5.5 Application to Experimental Data
1.6. 10.6 Damage Force Indicator Technique
1.6.1. 10.6.1 Identification of Single Delamination Through Damage Force Indicator
1.6.2. 10.6.2 Identification of Multiple Delamination Through Damage Force Indicator
1.6.3. 10.6.3 Sensitivity of Damage Force Indicator Due to Variation in Delamination Size
1.6.4. 10.6.4 Sensitivity of Damage Force Indicator Due to Variation in Delamination Depth
1.7. 10.7 Summary
1.8. References
2. 11 Use of Soft Computing Tools for Damage Detection
2.1. 11.1 Genetic Algorithms
2.1.1. 11.1.1. A Brief Introduction to Genetic Algorithms
2.1.2. 11.1.2. Genetic Algorithm Process for Damage Detection and Definitions
2.1.3. 11.1.3. Objective Functions in GA for Delamination Identification
2.1.4. 11.1.4. Case Studies with a Cantilever Beam
2.1.5. 11.1.5. Identification of Delamination Location, Size and Depth
2.2. 11.2 Artificial Neural Networks
2.2.1. 11.2.1. Simple Model of Neuron
2.2.2. 11.2.2. Types of Activation Function
2.2.3. 11.2.3. Multilayer Feedforward Networks
2.2.4. 11.2.4. Neural Network Integrated with SFEM
2.2.5. 11.2.5. Numerical Results and Discussion
2.3. 11.3. Summary
2.4. References
Index